Lamp



FIG. 1 is a perspective view of a lamp showing my new design;

FIG. 2 is a front elevation view thereof, a rear elevation view, a left side elevation view, and a right side elevation view being the same image thereof;

FIG. 3 is a top plan view thereof; and,

FIG. 4 is a bottom plan view thereof.

The broken lines in the drawings illustrate portions of the lamp which form no part of the claimed design. 

CLAIM The ornamental design for a lamp, as shown and described. 